The inventive composition comprises a combination of a neutral or basic alkali metal salt of a phenol sulfurized using elemental sulfur, a metal salt of a dithiophosphoric acid, an ashless dispersant, a calcium or magnesium sulfonate detergent, and a manganese carboxylate.
The sulfurization of phenols is well known. U.S. Pat. No. 2,207,719 discloses a process in which a phenol or an alkylphenol is reacted with elemental sulfur to form molecules which are believed to be phenol disulfides or monosulfides.
U.S. Pat. No. 2,370,302 discloses the use of sulfurized phenates in lubricating compositions which are subjected to high temperatures. In particular, the invention is aimed at lubricating oils used in internal combustion engines.
U.S. Pat. No. 2,409,687 discloses the use of sulfur monochloride as a reagent for the sulfurization of alkylphenols.
U.S. Pat. No. 3,285,854 discloses the use of thiobisphenolic compounds to improve the stability of nonash-forming nitrogen-containing detergents in oil. Among the nitrogen-containing detergents disclosed are N-dialkylamino alkyl alkenyl succinimides illustrated by the compound N-dimethylamino propyl polybutenyl succinimide.
U.S. Pat. No. 3,367,867 discloses the use of overbased sulfurized calcium alkylphenates as detergents in lubricating oils. The method of sulfurization of the phenol is not critical to the invention.
U.S. Pat. No. 3,929,654 discloses the preparation of an additive for lubricating and fuel oils which is prepared by reacting an alkylphenol with sulfur in the presence of an organic amine.
U.S. Pat. No. 4,010,106 discloses functional fluid lubricating oil compositions which comprise an oil of lubricating viscosity and an effective amount of each of the following materials: 1) an alkenyl succinimide, 2) a Group II metal salt of a dihydrocarbyl dithiophosphoric acid, 3) a frictional modifier, 4) a basic sulfurized alkaline earth metal alkylphenate, and 5) a chlorinated olefin containing from about 15 to 50 carbon atoms, from 20 to 60% by weight chlorine, and having a boiling point of at least about 300.5.degree. F. The chlorinated olefin may be present in the final functional fluid at levels ranging from 0.01 to 25% by weight, and more preferably from 0.05 to 0.5% by weight, and is particularly important in retarding corrosion of copper alloy parts within automatic transmissions.
U.S. Pat. No. 4,191,659 describes a method for the preparation of sulfurized compositions by reacting, under superatmospheric pressure, an olefinic compound with a mixture of sulfur and hydrogen sulfide in the presence of an acidic, basic or neutral catalyst, followed by removal of low boiling materials including unreacted olefin, mercaptan and monosulfide. An optional final step is removal of active sulfur; for example, by treatment with an alkali metal sulfide. The sulfurized compositions are stated to be useful as lubricant additives.
U.S. Pat. No. 4,874,007 discloses a process for preparing sulfurized alkyl-substituted phenols which are useful in preparing neutral and overbased phenate detergents.
British Patent 946,032 discloses a combination of sulfurated phenols and alkenyl-substituted succinimides. The succinimides are produced by reacting a polyalkenyl succinic anhydride with dialkylamino alkylamines.
U.S. Pat. No. 3,522,179 discloses lubricating compositions containing esters of hydrocarbon-substituted succinic acid. The hydrocarbon substituents generally have a molecular weight from 700 to 5000, although higher molecular weights may be employed. The alcohols from which the esters may be derived preferably contain up to 40 aliphatic carbon atoms.
U.S. Pat. No. 3,634,515 discloses the condensation product of a substituted alkyl phenol, an alkaline polyamine, formaldehyde and an aldehyde reactant having more than one carbon atom or a ketone reactant or mixture of both reactants.
U.S. Pat. No. 3,804,763 discloses dispersant compositions in which a carboxylic acylating agent is reacted with a hydroxy compound and also with a polyoxyalkylene polyamine.
U.S. Pat. No. 3,442,808 discloses that conventional Mannich condensation products may be further reacted with polyalkenyl succinic anhydrides to form a useful oil additive.
U.S. Pat. No. 4,867,890 titled "LUBRICATING OIL COMPOSITIONS CONTAINING ZINC DIHYDROCARBYLDITHIOPHOSPHATE, METAL DETERGENT, AND A COPPER COMPOUND" discloses a lubricating oil composition having improved properties which comprises a major proportion by weight of a lubricating oil, a dispersant compound, from 0.01 to 0.5 wt. % phosphorous and zinc and 5 to 500 parts per million of copper, and additive concentrates for blending with oil to produce such lubricating compositions.
Metal salts of phosphorodithioic acids are known lubricant additives. See, for example, U.S. Pat. Nos. 3,390,082 and 4,326,972. Metal salts of mixtures of phosphorodithioic acids and carboxylic acids are also known lubricant additives. See, for example, U.S. Pat. No. 4,308,154.
Preparations of phosphorodithioic acid usually involve the reaction of phosphorus pentasulfide (P.sub.2 S.sub.5) and an alcohol or a phenol.
U.S. Pat. No. 4,289,635 discloses molybdenum-containing compositions prepared by reacting an olefinically unsaturated compound capable of reacting with active sulfur with a composition prepared by reacting (a) a phosphorus containing acid represented by the formula ##STR1## wherein each X and X' is independently oxygen or sulfur, each n is 0 or 1 and each R is independently the same or different hydrocarbon-based radical, and (b) at least one hexavalent molybdenum oxide compound, and (c) hydrogen sulfide, in the presence of (d) a polar solvent. These compositions are described as being useful as additives for lubricants.
British Patent No. 1,105,729 describes a process for preparing a metal salts of a phosphorus acid comprising the reaction of a Group II metal base with a phosphorus acid of the structural formula ##STR2## (wherein X is oxygen or sulfur, at least one X being sulfur, and each R is a substantially hydrocarbon or a substantially hydrocarbonoxy radical with the proviso that one R can be hydrogen) wherein the reaction is carried out in the presence of a catalyst selected from carboxylic acids having up to 10 aliphatic carbon atoms and salts thereof with a metal. The metal salts prepared in accordance with British Patent No. 1,105,729 are stated to be useful, among other applications, as additives in hydrocarbon compositions, lubricants, fuels and greases.